Engineering Wonders of the World
Volume III

246 ENGINEERING WONDERS OF THE WORLD. Th© waste weir of Lake Fife is even larger than those of Lake Whiting, for it is able to pass 75,000 cubic feet per second. On its , , crest, 1,200 feet long, are eighty-eight gates, each 10 feet wide and 8 feet high, working on a unique principle. The gates are in pairs, the heavier of the pair opening downwards, the lighter upwards. When the heavy one rises the light one falls by its own weight, while, on the other hand, the descent of the heavy gate pulls up the other. The gates open and close automatically, through the operation of a counterweight, which is affected by changes in the level of the water passing through, the weir. This ingenious arrangement dispenses with the necessity for working the gates by hand when a flood occurs. The Marikanave reservoir in Mysore is a proof of the interest taken by the native ruler of an independent State in works of improve- ment. It was due to the energy of the late Sir Sheshadri Iyer, and to the warm support of her Highness the Maharani, that this great enterprise was carried out. The reservoir water is impounded by a dam built across a gorge about 1,200 feet wide at the crest of the dam, which is 142 feet above the river bed, and from the foundations has a maximum height of 167 feet. The reservoir will store a depth of 130 feet near the dam, and the water will spread over an area of 34 square miles. The maxi- mum amount that can be stored is calculated at 40,000,000,000 cubic feet, but such a quan- tity would collect only after unprecedented floods. The reason why the ultimate capacity is so greatly in excess of the ordinary volume (10,000,000,000 cubic feet) that will be im- pounded is interesting. It was proposed ori- ginally to provide a capacity of 20,000,000,000 cubic feet; but as a cyclonic rainfall would fill the reservoir and require a large escape to save the dam, it was found to be cheaper to Marikanave Reservoir and Dam. increase the height of the dam and enable the reservoir to absorb th© storm waters instead of allowing them to pass forward down the river. The life of an irrigation engineer in India is often a very lonely one, especially on some of the Punjab systems, where vast tracts of land have been reclaimed quite recently from almost absolute desert. There, for weeks, perhaps months, at a stretch he may never see another IrriSa” European, and have to sub- tion ncer s Life. sist on very simple fare. The recompense of such a life is that it brings him into very intimate contact with the agricul- turist and his daily toil, his patient persever- ance, his generosity to friends in distress. In short, he sees a great deal of the best side of the Indian “ryot.” But it is when famine stalks the land that the engineer reaps his best reward. One engineer, who has now retired from the Indian service, spent some years of his Indian life on the construction of a system lying south of the Ganges. He saw it com- menced ; he saw it finished. Much later, he was responsible for the administration of that system when it was irrigating some 500,000 acres of crops in the year. At that time, also, he was responsible to some extent for the works in another district north of the Ganges, where there were no canals. It was his duty to visit both. A time of scarcity and of famine came. The rainfall in the “ khareef ” season —the season when the rice is grown—failed, and there was difficulty in ... £ A Contrast, even raising the seedlings ot the crop which are transplanted subsequently into the fields. The ground was too hard to plough. Under the irrigation from the canals south of the Ganges, the crop was raised, transplanted, and watered. But this not with- out difficulty, so great was the demand, so hasty the people sometimes. North of the Ganges, where there were no canals, only a